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Mail sent from non users received by users on same domain exchange 2003

I'm receiving alot of spam from non users on my domain addressed to valid users.

I'm running exchange 2003 with the latest service pack along with mail essentials from gfi.

Other spam is being blocked properly.

Any idea's why this is happening?

Thanks

Mike

Just to clarify. Are you receiving mail from your own domain with fake user names?

john_991

ASKER

Yes, sent by fake users with the same domain name addressed to users who are on the domain.

i.e. Sent from abc@ere.com who is not on the domain addressed to xyz@ere.com who is on the domain.

Govvy

This will be spoofing performed by spambots external to your organisation marking the sender field with your smtp address. It is likely that your spam filtering solution has an exception for your domain name which you should remove to address this issue

Mike

Your being spoofed. You should contact you ISP about adding an SPF record to your DNS entries.

Mike

This will be helpfull in the process. Most ISPs will require you to submit the what you what the DNS entry to be.

http://www.openspf.org/

Mike

Just a heads up. If you are being spoofed it is possible other people than the people in your domain may be receiving these spoofed e-mails as well.

john_991

ASKER

I have this already in my dns server (spf record)

ere.com. 60 IN TXT "v=spf1 a ~all"

any other idea's?

Mike

To clarify: In "your" DNS server? Do you mean in your internal DNS (.local, etc) or public (.com, etc).

Also, Check out one of the e-mails headers to see where it actually came from. It is possible that you have a client with a spam-bot doing this.

john_991

ASKER

It's in the external dns server. (my hosting company's dns server)

Will look at the header soon.

ASKER CERTIFIED SOLUTION

Jamie McKillop

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